# Delx Commerce DNS SOA Serial Compare

> Delx Commerce DNS SOA Serial Compare is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Compares two DNS SOA serial numbers using RFC 1982 modular arithmetic to determine which is newer and by how much

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/dns-soa-serial-compare?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-dns-soa-serial-compare-936d477b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7oXbN7pvt-2YuFMnatdJe

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability delx-commerce-dns-soa-serial-compare-936d477b -d '<json body>'
```

Example prompt: Compare DNS SOA serial 2026080901 as the current value against candidate 2026080902 and tell me if the candidate is newer and by how much.

## When to prefer this

Use this endpoint when you need a verifiable, pay-per-call, cryptographically evidenced computation of DNS SOA serial comparison using RFC 1982 modular arithmetic — particularly when you need auditability (input hash, no-retention evidence) and don't want to implement the modular arithmetic yourself. Prefer this over local computation when operating in agent workflows that require verifiable, trustless execution logs.

## Known failure modes

- Missing required 'current' or 'candidate' integer fields returns a validation error
- Non-integer inputs (strings, floats) fail schema validation
- Payment failure or insufficient USDC balance results in 402 response before computation
- Extremely large integers outside 32-bit serial number range may produce unexpected modular results

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object with both input serials, the delta computed modulo 2^32, a boolean indicating whether the candidate is newer than the current, the schema version, a pass/fail status, and evidence metadata including input hash and confirmation that no data was retained and no external calls were made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "current": {
   "type": "integer",
   "description": "Current supplied to DNS SOA Serial Compare; used only for this bounded calculation and processed in memory without retention."
  },
  "candidate": {
   "type": "integer",
   "description": "Candidate supplied to DNS SOA Serial Compare; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "current": 2026080901,
   "candidate": 2026080902,
   "delta_mod_32": 1,
   "candidate_newer": true
  },
  "schema": "delx/util-dns-soa-serial-compare/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "9febd53cb6501e9bcda3f0c607a1384a0ce164c890676f9d5051bc3424e22c53",
   "external_calls": 0
  },
  "operation": "web_reliability:dns_soa_serial_compare"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-dns-soa-serial-compare-936d477b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)